Stone tools unearthed at a Brazilian rock-shelter may date to as early as 22,000 years ago. Their discovery has rekindled debate about whether ancient people reached the Americas long before the famed Clovis hunters spread through parts of North America around 13,000 years ago.

These relics of ancient South Americans add to evidence from nearby sites challenging the longstanding view of Clovis people as the first Americans (SN: 8/11/12, p. 15), a team led by geochronologist Christelle Lahay...